Azo dye and process of making same.



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THllLU KROEBER AN D CARL Ji lGlCltElPACl-lER, 0F BASEL, SWlTlTZERlQAND,

ASSIGNORS TU THE FIRM ()F SOOlQElTY OF (JllltMIOAL lNl'lUET BASLE, (ll lAEdlCL, Sl l FllT/il illtLANlJ.

$pecification of Letters Patent.

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Patented Aug. 15, 1905.

Application filed May 23, 1905. Serial No. 261,897.

To a whom it III/(by concern:

Be it known that we, TnILo Knonnnn, chemist and doctor of hilosophy, a subject of the Duke of Saxe-Altcnburg, and CAM. JAGERSPAOHER, chemist and doctor of phi.- losophy, a subject of the Emperor of Austria- Hungary, both residents of Basel, EiWlhZOI land, have invented new and useful improvements in the Manufacture of lvlonoazo l)yc stu'lls, of which the following is a clear and complete specification.

According to published statements (Berliner Ber. XXVll, 23) .nitrous acid acts on the sulfonic acids of 1:Z-amidonaphtliol with formation of corresponding quinone acids that is to say, its action is the same as that of nitric acid-namely, an oxidation. in German patent specification No. 155,033, it is stated that 1:2:4: a111idonaphtholsulfonic acid, for example, in the presence of organic acids may be diazotized and the d iazo compound maybe combined with resorcinol. As a fact in this case also the process leads to the formation in considerable proportion of quinone acid as can be gathered from the evolution of red vapors and by the formation of naphtho uinoneanil when a sample of the diazotized iquid is heated with anilin, while there is produced in small proportion with resorcinol a dyestu'lf soluble in soda-lye to a violet-colored solution. Thus the existence of a normal diazonaphtholsulfonic acid is still very doubtful.

l Ve have made the surprising discovery that by introducing an acid radicle into the molecule of the ai'nidonaphtholsulfonic acid the object can be attained. if, for example, the basic sodium salt of 1:2: t-amidonaphtholsulfonic acid treated with the calculated proportion or with a slight excess of acetic anhydrid. at a reduced or at ordn'iary temperature, acetylization occurs, the acetyl there is obtained a diazo compound which separates as yellow crystals and may be easily coupled with azo dyestul'l' components. From its behavior it appears to be ortho-acct oxydiazonaphthionic acid. it combines, for example, with. beta-naphthol to form a red dyestull' which gradually or more quickly when warmed passes to a greenish-blue dyestuff in consequence of the elimination of the acetyl group. This elimination occurs also when the said diazo compound is allowed to remain long at rest. Already after the lapse of an hour it is found that a sample treated with an alkaline solution of betanaphthol does not combine immediately and with a red color, but more gradually with a yollowishgreen and later a blue color, a behavior which must be ascribed to the diazonaphtholsulfonic acid, which indeed is characterized by great stability toward heat, however, as was to be expected, differs by the more gradual coupling tendency from the corresponding acetyl derivative. The (liazonaphtholsulfonic acid is somewhat sparingly soluble in water containing mineral salts, but more easily soluble in pure water. It is easily obtained as beautiful small lustrous lamina) by preparing the aforesaid diazo-acetnaphtholsulfonic acid in. a somewhat dilute solution, eliminating the acetyl group either by leaving the solution to itself or quite gently warming it and mixing the clear solution with common salt or potas- 'sium chlorid. YVhen a stronger solution. is being worked, the separation occurs even without common salt.

The manufacture is illustrated. by the following example.

29.9 kilos of 1 :2-amidonaphthol-+l-sulfonic acid are dissolved in two hundred liters of water with aid of forty-nine kilos of soda-lye of 30 Baume and acetylized by means of eleven kilos of acetic anhydrid at a temperaturebelow 0 centigrade while good stirring maintained. After a short time there are added to the solution which should. have neutral or feebly alkaline reaction, seven kilos of solid sodium nitrite, and the whole is acidified at 0 centigrade by adding all at once thirty kilos of ordinary hydro chloric acid, whereupon the iinass immediately solidifies without any evolution of gas to a yellow crystalline magma, This diazocompound is allowed to flow immediately into an aqueous solution of sixteen kilos of 1:6-dioxynaphthalene containing twentyeight kilos of caustic-soda lye of thirty per cent. strength. At first a violet dyestuff is formed, which already after short stirring passes to a green-blue dyestuff. To isolate it, the liquid is acidified with hydrochloric acid and mixed with common salt. The dyestuff may eventually be purified by redissolving. The dyestuff thus obtained dissolves in water with a violet coloration and in concentrated sulfuric acid with a greenblue coloration. It dyes unmordanted wool in an acidbath deep bordeaux tints, which" pass to deep greenish-black when. subse- 'quently treated with chromium compounds.

* furic acid with a blue coloration and dyes wool in an acid-bath bordeaux tints, passing by subsequent treatment with chromium compounds to blue-black. 1:8-dioxynaphthalene gives a dyestuff which dyes wool in an acid-bath blue tints, becoming black by treatment with bichromate.

What we claim is- 1. The process for the manufacture of monoazo dyestuffs, which consists in acidylizing sulfonic acids of 1: 2-amidonaphthol in the hydroxyl group, then diazotizing the soobtained 1amido-2-acidyl-oxynaphthalenesulfonic acid and combining the resulting diazo compound with an azo coloring-matter component, as described.

2. The process for the manufacture of monoazo dyestuffs, which consists in acetylizing l 2amidonaphtholsulfonic acids in the hydroxyl group by treating their basic alkali salts in aqueous solution with acetic anhydrid, then diazotizing the so-obtained l-amido2acetoxynaphthalenesulfonic acids and combining the resulting diazo compound with an azo coloring-matter component, substantially as described.

3. An improvement in the manufacture of monoazo dyestuffs, consisting in the process for the manufacture of 1-amido-2-acetoxynaphthalenesulfonic acids, by treating the basic alkali salts of 1:2-amidonaphtholsulfonic acids with acetic anhydrid in an aqueous solution, substantially as described.

4. An improvement in the manufacture of monoazo dyestuffs, consisting in the manufacture of 1amido-2acetoxynaphthalene4 sulfonic acid, by treating the basic sodium salt of 1 2amidonaphtholl-sulfonic acid in an aqueous solution with acetic anhydrid.

5. The process for the manufacture of monoazo dyestuffs, which process consists in acetylizing the basic sodium salt of 1 2amido naphthol-4-sulfonic acid, diazotizing the soobtained 1-amido-2-acetoxynaphthalenelsulfonic acid, then combining the resulting diazo compound with an azo coloring-matter component, substantially as described.

6. The process for the manufacture of a monoazo dyestuff, which process consists in acetylizing the basic sodium salt of 1:2- amidonaphthol-4-sulfonic acid, diazotizing the so-obtained 1.-amido2acetoxynaphthale11e-4-sulfonic acid, then combining the resulting diazo compound with 1 6-dioxynaphthalene, substantially as described.

7. As new products the monoazo dyestuffs, containing sulfonic acids of 1:2-diazonaphthol, which dyestuffs dissolve in water with violet and in concentrated sulfuric acid with violet to blue colorations and which dye unmordanted wool in bordeaux to violet tints which tints become on treatment with chromium compounds blue to black.

8. As new products the monoazo dyestuffs, containing the 1 2diazonaphtholl-sulfonic acid, which dyestuffs dissolve in water with violet and in concentrated sulfuric acid with violet to blue colorations and which dye unmordanted wool in bordeaux to violet tints which tints become on treatment with chromium compounds blue to black.

9. As a new product the monoazo dyestuff, derived from 1 2amidonaphthol4sulfonic acid and 1:6-dioxynaphthalene, which coloring-matter yields a violet aqueous solution, dissolves in concentrated sulfuric acid with greenish-blue coloration, and dyes unmordanted wool in bordeaux shades, which shades become greenish black on treatment with chromium compounds, substantially as described.

In witness whereofwe have hereunto signed our names, this 9th day of May, 1905, in the presence of two subscribing witnesses.

THILO KROEBER. CARL JAGERSPACHER.

IVitnesses ALBERT GRAEBER, AMAND RITTER. 

